Country music has grown from humble origins into one of the largest sectors in the American entertainment industry, but none of its current superstars will ever attain the mythic aura of Johnny Cash who has died of complications from diabetes aged 71. While during the 1970s and 1980s, Cash found himself out of favour in country music's hometown of Nashville, he, as his step-daughter Carlene Carter put it, "built that town in a lot of ways." It took the hip hop/heavy metal entrepreneur Rick Rubin to appreciate how much Cash had meant, and how much he still had to offer.

Rubin invited Cash to make an album on his American record label. The result, 1994's American Recordings, featured just Cash, his acoustic guitar and that great booming baritone voice, playing songs by Leonard Cohen, Tom Waits and Kris Kristofferson alongside strong material of his own. Forty years after he had begun his professional career with Sun Records in Memphis, Cash had returned to renew his claim to being a great country singer and an American legend.

Cash was born in Kingsland, Arkansas, and remembered, when he was three, the family moving to Dyess Colony on the Mississippi delta in 1935, where his father Ray worked on a federal land-reclamation scheme. The entire family, my parents, two brothers and two sisters spent the first night in the truck under a tarpaulin," Cash recalled. "The last thing I remember before going to sleep was my mother beating time on the old Sears-Roebuck guitar, singing 'What Would You Give In Exchange For Your Soul'." Cash's 1959 hit record, Five Feet High and Rising, recalled the night when the Cash family had to be evacuated when the river overflowed.

Living and working by the "Big River" as a child Cash soaked up work songs, church music, and country and western from radio station WMPS in Memphis, or the broadcasts from Nashville's Grand Ole Opry on Friday and Saturday evenings. At night, he stayed awake to listen to music drifting up from the Mexican border stations. Johnny got religion when he was 12, and the death of his brother Jack in an accident with a circular saw intensified his faith to the point of fervour.

He graduated from Dyess High School in 1950, headed north to Detroit, and found a job in a car-body factory in Pontiac, Michigan. However, he rapidly thought better of it, and signed up for the United States Air Force. He was posted to Landsberg, West Germany, and worked as a radio intercept officer, eavesdropping on Soviet radio traffic. It was in Germany that he began to cut his musical teeth, teaching himself the guitar, trying his hand at songwriting, and playing in a band called the Landsberg Barbarians.

"We were terrible," he said later, "but that Lowenbrau beer will make you feel like you're great. We'd take our instruments to these honky-tonks and play until they threw us out or a fight started. I wrote Folsom Prison Blues in Germany in 1953."

Back in the US he married Vivian Liberto, whom he had met during his basic training in Texas, and the newlyweds moved to Memphis. At first, Johnny struggled to make a living as a household appliance salesman, but then his older brother Roy, also living in Memphis, introduced him to the Tennessee Three - Luther Perkins and Marshall Grant, plus AW "Red" Kernodle on steel guitar.

The foursome gained experience playing parties and church functions, while Cash mounted a persistent campaign to persuade Sam Phillips, who ran Memphis's Sun Studios, to grant them an audition. Phillips finally succumbed and summoned the group to play for him in the spring of 1955. It was all too much for an overawed Kernodle, who never turned up, but the remaining three turned in a sparse, vibrant rendition of a brand new Cash song, Hey Porter. The interplay between Grant's thumping bass, Perkins's jittery lead guitar and Cash's choked strumming was, in its way, as revolutionary as anything Elvis Presley or Carl Perkins would accomplish with Sun.

Phillips was duly impressed, despatched Cash to write a hit single, and by the summer Johnny Cash and the newly-named Tennessee Two had their first hit record, Cry, Cry, Cry coupled with Hey Porter on the B side. Classic songs were soon pouring out of Cash. His next release was Folsom Prison Blues, then came I Walk The Line, Big River, Home Of The Blues and Guess Things Happen That Way.

While at Sun, Cash also wrote You're My Baby for Roy Orbison and Get Rhythm for Elvis Presley, though Cash described how, when Sam Phillips sold his interest in Presley to RCA, he wouldn't allow Elvis to take Get Rhythm with him, and put it on the B side of Cash's I Walk The Line instead. "The Elvis I knew was a kid full of fun," said Cash. "He loved his work, loved his music, loved his guitar, loved gospel music and loved his mother."

Sun's first-ever album release was Johnny Cash With His Hot And Blue Guitar, but the tight-fisted Phillips decided he wanted no further Cash albums, and also didn't fancy increasing the rising star's royalty rate. Cash's response was to move to Columbia Records in 1958, simultaneously transplanting his band, family and manager to Los Angeles. His first Columbia album, 1959's The Fabulous Johnny Cash, was also his first US album chart entry, reaching number 19, and hit singles were not long in coming, in the shape of Don't Take Your Guns To Town, I Got Stripes, Five Feet High And Rising and The Ballad Of Johnny Yuma. In January 1960, he played the first of his celebrated prison shows at San Quentin, where one of the inmates yelling him on was Merle Haggard, locked up on a burglary charge.

With growing success came mounting pressures and demands. Scheduled to play up to 300 concerts a year, Cash found himself becoming increasingly dependent on amphetamines to keep going, even though he knew it was affecting his writing and his recorded work. The quantity of his output remained high, but the quality grew erratic, with Ring Of Fire his only big hit of the early 1960s. The flip side of Cash's gritty, carved-from-stone persona was a tendency to earnest preachiness, and this came to the fore in a string of long-winded "concept" albums like Ride This Train (1960), Blood, Sweat And Tears (1963) and True West (1965). Whereas Cash's original strength had been his ability to get to the point with the minimum of fuss, now he was growing pontifical.

Not that all his work form this period was without significance. For instance, his 1964 album Bitter Tears, subtitled Ballads Of The American Indian, included Cash's memorable treatment of Pete LaFarge's Ballad Of Ira Hayes, and was the first of many instances of Cash's willingness to speak up for outcasts and underdogs.

His problems with drugs landed him in trouble through bizarre incidents like driving a tractor into the lake behind his new house in Hendersonville, near Nashville, and inadvertently starting a forest fire which cost him an $85,000 fine. His pill-popping reached crisis point in 1965, when he was jailed for three days after being arrested in El Paso, smuggling amphetamines into the US across the Mexican border.

Perhaps inevitably, his addiction affected his family life (even though he had managed to find time in his hectic schedule to sire four daughters, including Rosanne who would become a respected singer/songwriter), and Vivian eventually divorced him in 1967. Luckily for Cash, he had already met June Carter, who had co-written Ring Of Fire with Merle Kilgore. The Carter clan was one of the legendary dynasties of country music, and in the 1940s, June and her sisters Helen and Anita would perform regularly with their mother, as Mother Maybelle and the Carter Sisters.

During the 1960s, as he became increasingly fascinated by the scope and history of American popular music, Cash frequently included the Carter Family in his own live shows. Johnny and June scored a big hit with their duet version of Jackson in 1967.

They married in 1968, after Johnny had dramatically proposed to June onstage in London, Ontario, the previous autumn. "The love that John and I share with our love for Christ is one of the most precious gifts God could have given us," she would write later. She devoted herself to the twin pillars in her life, God and Johnny Cash, and was determined to make her husband end his amphetamine addiction.

Cash's career began to take on a broader, clearer shape. His 1968 album, Johnny Cash at Folsom Prison, was a huge success and is still widely regarded as one of the finest country records ever made. In June 1969, The Johnny Cash Show began on ABC-TV. Based in Nashville, the show pulled in artists from every conceivable genre, highlighting the breadth of Cash's tastes. Among guests who appeared on the 88 shows Cash recorded were The Who, Mahalia Jackson, Neil Young, Louis Armstrong and Bob Dylan (Cash struck up a rapport with Dylan which led to them duetting on Girl From The North Country, on Dylan's 1969 country album Nashville Skyline, for which Cash also wrote sleeve notes).

Career highlights continued to accrue. Johnny Cash at San Quentin (1969) spawned a monster hit single with the tongue-in-cheek A Boy Named Sue, and the Cash/Carter duet on If I Were A Carpenter enjoyed further chart-success and scored a Grammy award. In 1971, Cash recorded the Man In Black album, the title song containing a somewhat melodramatic declaration of intent:

I wear the black for the poor and the beaten down, living in the hopeless, hungry side of town I wear it for the prisoner who has long paid for his crime...

Cash was growing into his persona as American icon and beacon of integrity, even if there were those who found the Johnny and June act somewhat overloaded with treacly religiosity. The Man In Black album even featured an appearance by celebrity evangelist Billy Graham.

Cash's commanding presence lent itself to screen appearances. Trivia buffs may recall his minor role in an episode of the 1960s Clint Eastwood/Eric Fleming TV western series Rawhide, though he received greater acclaim for his appearance with Kirk Douglas in A Gunfight (1972), and he went on to appear in a string of TV movies including The Pride Of Jesse Hallam (1980), Murder In Coweta County (1983), The Baron And The Kid (1984), and The Last Days Of Frank And Jesse (1986). He appeared in episodes of Columbo, and in 1993, he popped up in the TV series Dr Quinn, Medicine Woman.

He had achieved an apparently unassailable status, but by Cash's own admission, "around 1972 or 1973, the excitement went out of my recording career." He could still make hits, like One Piece At A Time or Ghost Riders In The Sky, but while Cash himself had been capable of making tosh like The Holy Land (1970), he could still recognise that the stuff being peddled as "country" music was too middle of the road for a veteran of the hard-rockin' Sun years like himself.

Columbia's ending of their 28-year relationship with the singer in 1986 stands as one of the greatest gaffes ever perpetrated by the record business, and it rankled with Cash more than he liked to acknowledge. Still, he was rapidly signed by Mercury, with whom he recorded a batch of convincing albums including Johnny Cash Is Coming To Town (1987), Water From The Wells Of Home (1988) and Boom Chicka Boom (1990), the latter kicking off with Cash's trademark observation, "Hello, I'm Johnny Cash." Also during the 1980s, Cash teamed up with Willie Nelson, Waylon Jennings and Kris Kristofferson to form the successful recording and touring outfit, The Highwaymen.

In 1988, Cash had to undergo double heart bypass surgery in Nashville, a warning bell which triggered a re-evaluation of his remarkable career by younger generations of listeners. That year, the British Red Rhino label issued 'Til Things Are Brighter, featuring young artists covering Cash songs to raise money for Aids research, and Cash was greatly touched by it. In 1992, he was inducted into the Rock And Roll Hall Of Fame in New York, and that autumn Johnny and June performed It Ain't Me Babe at the Madison Square Garden concert commemorating Bob Dylan's 30 years in the music business.

In 1993, Cash's gravelly baritone featured on The Wanderer, from U2's Zooropa album ("I was thrilled to death, because I love that song," Cash enthused), and in 1994 the American Recordings album amounted to a complete reappraisal of the legend of Johnny Cash, and one which found a ready new audience. An appearance at the Glastonbury Festival boosted his burgeoning new profile. A second album on the American label, Unchained, was released in November 1996, and found Cash mixing vintage country tunes by Jimmie Rodgers and the Louvin Brothers with "alternative rock" songs from Soundgarden and Beck.

He went on to make three more albums for American, with 2002's The Man Comes Around in particular earning rapturous critical acclaim for Cash's commanding reinventions of Bridge Over Troubled Water, Desperado and Depeche Mode's Personal Jesus.

Given Johnny's precarious health, it was a cruel irony that he was pre-deceased by June last May, after she had undergone heart surgery. This wasn't long after Johnny had guested on his daughter Rosanne's album, Rules Of Travel, singing lyrics which clearly signalled his own fragile mortality - "I cannot move mountains now, I can no longer run".

Johnny Cash was a country musician who was too big for country music, and his work as artist, humanitarian, and patron of songs and songwriters will endure indefinitely.

· Johnny Cash, musician;, born February 26 1932; died September 12 2003